Earth's surface waterApproximately one-thirdThe Caspian Sea is the world's largest lake, occupying about 1.2 million square kilometers. According to a study published in the journal Nature in April 2025, the Caspian Sea will have lost more water by 2100 than it did in 1990.-27.5 metersThe water level could drop by up to 21 meters based on the Furthermore, it is noted that just a 5 meter drop in water level would eliminate 201 TP3T of the current area of the Caspian Sea. Moreover, only a5m~10mIt has been noted that even a drop in the water level of the

It was the fourth largest lake in the worldAral Seawas reduced to less than one-tenth of its original area due to large-scale irrigation projects undertaken since the 1960s,desertificationWill the Caspian Sea disappear as it is disappearing? We will explore the current status of the Caspian Sea and its impact.

The Caspian Sea photographed from the International Space Station (Photo:Alexander Gerst / Flickr [CC BY-NC-SA 2.0])

Basic Information on Caspian Sea

First, we would like to understand some basic information about the Caspian Sea. The Caspian Sea is located east of the Caucasus Mountains and borders a total of five countries: Kazakhstan, Turkmenistan, Iran, Azerbaijan, and Russia. The main rivers that connect to the Caspian Sea are the Volga, the Urals, and the Terre in the north, and the volume of water flowing into the Caspian Sea from these rivers is about 1.5 times the total volume of water in the whole of the Caspian Sea.88%The Caspian Sea occupies the largest portion of the country's territory. On the other hand, there are no permanent rivers on the eastern shore of the Caspian Sea, except for the Atrak River in southern Turkmenistan. In addition, although the water that flows into the Caspian Sea from the river is freshwater, the soil in theSalt and mineral componentsis dissolved into the Caspian Sea and cannot be used as fresh water.

With such abundant water resources, many ethnic groups, including the Caspian people, from whom it takes its name, have made the Caspian Sea and its vicinity their base of operations.Silk RoadIt is also a part of the "Balkans" and has served as an important center of trade, culture, and diplomacy from ancient times to the present. Today, it serves as a route for trade from Asian countries to Europe without having to go through Russia,Trans-Caspian international shipping route."It is noted by the name of

The most important resources obtained from the Caspian Sea are natural gas and oil; in 2022, natural gas production in the offshore Caspian Sea will be the largest source of natural gas supply in the world.Approx. 3%and oil production accounted for 11 TP3T of the world's oil supply. It is also very famous for its fishing industry, especially caviar from sturgeon in the Caspian Sea.number oneThe company boasts a production volume of

Babolzar beach in Iran on the Caspian Sea (Photo:daniyal62 / Flickr [CC BY-NC 2.0])

Who owns the Caspian Sea?

The Caspian Sea, a treasure trove of natural gas and oil, has long been the scene of international wrangling over "who owns it." Before the collapse of the Soviet Union in 1991, the Caspian Sea wascontrolThe only two countries that had claimed the Caspian Sea were Iran and the Soviet Union. However, after the collapse of the Soviet Union, three newly established countries, Azerbaijan, Kazakhstan, and Turkmenistan, in addition to Iran and Russia, began to claim the Caspian Sea, and this dispute gradually intensified. For many years, the basic question of whether the Caspian Sea is a sea or a lakeDefinition.Not even the Caspian Sea had been decided. If the Caspian Sea were defined as a "sea" and the international maritime law were applied, other countries besides the coastal states could have access to the Caspian Sea, which could provide a legal basis for other countries' warships to sail through the Caspian Sea, and some countries were concerned and opposed to this. On the other hand, some countries opposed it because if the Caspian Sea were considered a "lake," an equal partition agreement among the five countries would apply, requiring an equal distribution of seabed resources regardless of the length or shortness of the coastline.

While the dispute over the boundary line remained unresolved, a number of incidents occurred in the littoral states: in 2001, the conflict between Iran and Azerbaijan over the development of hydrocarbon fields in the Caspian Seamilitary conflictThe situation even came to the verge of a crisis. After a long conflict, in 2018, the five coastal states finally agreed on the legal status of the Caspian Sea inagreementwas concluded. This gave the waters a "special legal status" different from seas and lakes, and the surface waters of the Caspian Sea are to be used in common by the coastal states. However, the specifics, such as the distribution of seabed resources, remain to be worked out,individual negotiationMany issues remain unresolved as they are left to the

Water Level Fluctuations and Pollution

While the Caspian Sea is thus a whirlwind of speculation among the five countries, the gradual fluctuation of its water level is having a serious impact on the region. Many studies exist on the Caspian Sea level fluctuations, but as mentioned at the beginning of this article, it is estimated that by 2100, the Caspian Sea will be at its highest level compared to today.21 metersIt has been noted that the water level could drop. Some estimate that a 5 meter drop in the water level would reduce the area of the Caspian Sea by 201 TP3T, exposing 77,000 square kilometers of land.

Loading...

this (something or someone close to the speaker (including the speaker), or ideas expressed by the speaker)figureshows the change in the water level of the Caspian Sea from 1990 to 2024 in Baku, the capital of Azerbaijan. The water level of the Caspian Sea showed year-to-year fluctuations in a long-term declining trend until 1978, which was mainly due to a decrease in water inflow caused by human activities such as irrigation and dam development. However, water levels rose sharply in the period from 1978 to about 1995. This rise is believed to have been caused by a decrease in evaporation due to a temporary drop in temperature in the Volga River basin and a reduction in irrigation projects.

Subsequently, water levels began to decline again after 1996, and in recent years the decline has been particularly sharp. Behind this is a decrease in precipitation and an increase in evaporation due to global warming, and changes in the industrial structure after the collapse of the Soviet Union are also thought to be influencing this trend. From this figure,climate changeand changes in human industrial activities have a significant impact on water level fluctuations.

The Caspian Sea coastline has undergone a series of advances and retreats, but the fluctuations in water levels, especially in the 20th century, were caused by changes in the volume of water flowing into the Caspian Sea and changes in precipitation and evaporation.causeIt is believed that the Caspian Sea is the largest river in the world. The Volga River in Russia influences the amount of water flowing into the Caspian Sea. of water flowing into the Caspian Sea.Approx. 80%As of 2021, Russia will be in the basin of this river that supplies the11 unitsThe Caspian Sea has a large number of dams, which have reduced the amount of water flowing into the Caspian Sea. Also, in 2022, coinciding with Russia's invasion of Ukraine, theintentionalIt has also been pointed out that this may have reduced the amount of water flowing into the Caspian Sea to more water from the Volga River for agricultural use in order for Russia to supplement its domestic production of agricultural products that it can no longer import due to economic sanctions imposed by Western countries.(before a negative form) even (e.g. "not even a single person")useIt is believed that they may have done so.

And even more likely to be affected by rising temperatures are changes in evaporation. One study found that the increase in evaporation in the Caspian Sea is more important than river inflows or precipitation in the Caspian Sea.changeBy 2100, the average temperature in the Caspian Sea is estimated to beApprox. 3.64 degreesWith predictions of an increase, evaporation is expected to continue to increase in the future.

The lowering of the water table has a particularly large impact on shallow water areas. World Database of Protected Areas(WDPA)According to the Caspian Sea Protected Area established by Kazakhstan, the entire Caspian Sea16.8%in the current area. However, since most of them are located along the coast, a 5-meter drop in water level is expected to reduce the area of the protected area to the current 71 TP3T, and a 10-meter drop to the current 11 TP3T. At this rate, it is very likely that the current protected area will disappear by 2100.

In addition, another problem that the Caspian Sea faces is water pollution. Due to large-scale oil and gas extraction, the water is being polluted by heavy metals such as mercury and cadmium, which are toxic to living organisms.pollutionhas been confirmed. There is also a possibility that toxic substances contained in the fuel of missiles fired from the Caspian Sea by Russia in connection with its invasion of Ukraine are falling into the Caspian Seapointing outThe pollution situation is further exacerbated by the fact that the Caspian Sea is a closed basin. Since the Caspian Sea is a closed basin, even if pollutants are discharged into the Caspian Sea, they do not flow out of the Caspian Sea.accumulation (sediment)The problem is that the number of people who are willing to do so is increasing.

Impact of Caspian Sea changes on the environment and people

These issues of environmental change and pollution are of great concern in terms of biodiversity. The Caspian Sea has222 typesIt is home to a valuable ecosystem of more than endemic invertebrates (excluding protozoa and parasites) and 31 endemic fish species, as well as Caspian seals. However, due to the unplanned actions of people, the ecosystem has been destroyed.

Caspian seal populations in the past century.90%Although the population has declined, from 1.2 million at the beginning of the 20th century to an estimated 75,000 to 270,000 today, future fluctuations in water levels could lead to further declines in Caspian seals. Historically, for most of the 20th century, the pelts and oils from Caspian sealsstate initiativeSeal hunting was conducted in the Caspian seal now by the International Union for Conservation of Nature (IUCN),endangered speciesdesignated as a "protected species," and although hunting of Caspian seals is now banned in five coastal countries, their numbers continue to decline.

In recent years, the Caspian seallarge number of deathshave been observed repeatedly. Although there are various theories as to the cause, water pollution and a decrease in sea ice extent are thought to be the main reasons. As mentioned above, water pollution in the Caspian Sea is serious. This pollution affects the immune system of the Caspian seal, which is the main cause of theinfectious diseaseIt has been suggested that this may have led to the expansion of the In fact, in October 2024, on the coast of the Republic of Dagestan, Russian Federation, where poorly treated wastewater is discharged into the Caspian Sea, sealsone large animal (horses, cattle, etc.)Only a few were recorded. Experts have pointed out the possibility that fish and other food sources for Caspian seals may also be infected with the toxin. It is also said that a reduction in the area of sea ice during the winter months will cause a shrinkage of the Caspian seal's habitat. Specifically, a 5-meter drop in water level can result in a maximum81%habitat shrinkage is expected to occur. Originally, Caspian seals migrate north in the winter to breed in the northern part of the country where there is sea ice, but they may lose their breeding grounds in the future.

Caspian seal in the Caspian Sea (photo:Aboutaleb Nadri / Wikimedia Commons [CC BY 4.0])

Sturgeon, which produce the famous caviar in the Caspian Sea, are also similarly affected by habitat and spawning areas. Shrinking areas of shallow water that are their habitat as a result of water level fluctuations may prevent sturgeon from migrating and reaching the rivers where they spawn. Such a change in the population of the species would mean a reduction in the fishing industry in the Caspian Sea. In addition, although the harvesting of sturgeon is currently prohibited, manyillegalThe fishery continues to catch sturgeon in the Catch of other fish is also in danger of declining. In Kazakhstan, for example, catfish and trout catches have been reduced, and temporaryCatch Ban MeasuresThe Caspian Sea has been shrinking and measures are being taken to prevent this. If the Caspian Sea continues to shrink, its salinity will become even denser, making it more inhospitable for Caspian Sea fish and possibly reducing catches.

This situation is also affecting human society. As catches have continued to decline in recent years, many fishermen in coastal countries are no longer able to sustain their livelihoods through fishing alone. Also, as the Caspian Sea shrinks, the toxic dust that has been deposited on the seafloor dries up and is carried by the wind,Millions of peopleThe increased risk of respiratory diseases in the sandstorms are becoming more frequent, and agriculture is being affected. For these reasons, of the 15 million people currently settled around the Caspian Sea, by mid-centuryUp to 5 millionmay be forced to migrate.

The Shrinking Caspian Sea and Its Geopolitical Implications

The Caspian Sea plays an important role as a strategic point for trade and energy transportation between Central Asia, Europe, and China. before the Russian invasion of Ukraine in 2022, the Caspian Sea was the main source of rail transportation between Europe and China.90%More than half of the trade routes were through Russia. However, since the economic sanctions, the expansion of trade routes not via Russia has been sought. In particular, the transoceanic international transport route is attracting attention as a route for the European Union (EU) to trade with China without going through Russia or Iran, and its geopolitical importance is increasing. Carried from China and other countries.goodswill cross the Caspian Sea from the ports of Aktau and Kulik on the Caspian Sea coast of Kazakhstan to Baku and Arat in Azerbaijan, from where they will be transported overland to Europe.

This transportation method eliminates the need to go through Russia and Iran, which have been subject to economic sanctions from Western countries, thus strengthening the supply chain for the EU and China. Especially since Russia's invasion of Ukraine, trade using international transoceanic transport routes has been increasing, and according to the World Bank's forecast, the volume of transport in 2030 is expected to increase from 2021 tothree timesIt is believed that this will be the first of its kind in the world. China and the EU already have high hopes for this corridor, and the logistics facilities needed for tradedevelopmentand Central Asian countries with the goal of improving transportation networks.investmentThe company has been

Middle CorridorBased on data from the

However, the risk of low Caspian Sea levels is beginning to cast a dark shadow over these economic initiatives.untradeableIt has been pointed out that this could be the case. On the other hand, the ports of Turkmenbashi in Turkmenistan and Lagan in Russia could, in the worst case, be 16 kilometers and 126 kilometers from the coast, respectively. In addition to ports, infrastructure facilities such as oil refineries and natural gas processing facilities could also increase their distance from the coastline by more than 5 kilometers. What are the economic losses associated with such water level fluctuations?Tens of billions of U.S. dollars per yearmay exceed the

In the midst of all this, another firestorm has emerged: the shortage of water resources, which GNV has also previouslyintroductionAs was the case in the previous section, the recent decline in water resources in Central Asia has led to the outbreak of conflicts for the acquisition of water resources. In the Caspian Sea, Kazakhstan, Azerbaijan, and Iran aredesalination plantare under construction or being considered. Desalination of Caspian Sea water, which has a lower salinity than ordinary seawater, iscostThis is because the water is relatively low. These countries plan to use this water for agriculture and for the production of domestic and green hydrogen. On the other hand, this desalinationenvironmental pollutionThe Caspian Sea is also a major source of water for the region, and there are concerns that it will cause the Caspian Sea to drop in the next few years and cause water levels to drop further, which could accelerate the upcoming conflict over Central Asia's water resources. Developments in the Caspian Sea are also crucial to regional stability.

COP29 and the Caspian Sea

In response to this situation, the 29th Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC), to be held in Baku, Azerbaijan, in 2024 (UNFCC COP29), the issue of declining water levels in the Caspian Sea was one of the main topics of discussion. However, the discussion did not proceed easily. Azerbaijan, the chairing country, was reluctant to limit fossil fuels, calling them "A Gift from GodIn some cases, he described the situation as "the most important thing in the world". However, such consumption of fossil fuels has caused climate change and led to the decline of the Caspian Sea, contradicting Azerbaijan's claims.

Mobile drilling rigs extracting oil in the Caspian Sea (Photo:www.dragonoil.com. / Wikimedia Commons [CC BY-SA 3.0])

In addition, Iran has done little to address climate change, which has accelerated the decline in the volume of water in the Caspian Sea over the past decade. For this reason, there were hopes that Iran's participation in COP29 would bring about a change in Iran's environmental protection policies. In reality, however, Iran's reluctance to take environmental protection measuresposturehas not changed, and the 2015Paris Agreement (1985)The COP29 also did not change the policy of not acceding to the Caspian Sea Protectionregional cooperationIt can be said that this report has highlighted the difficulty of It appears that each country is so focused on short-term national interests that they are neglecting long-term environmental conservation efforts. The Caspian Sea, which is geographically closed, cannot be effectively addressed without cooperation among countries.

On the other hand, we also see measures to address these problems caused by climate change: at COP29, Azerbaijan, Kazakhstan, and Uzbekistan,Tri-Party Agreement on Strategic Partnership in the Field of Green Energy Development and Transfer."The three countries plan to lay transmission cables across the Caspian Sea seabed and the Black Sea to supply renewable energy to Europe.

The region is one of the world's leading producers of renewable energypotentialand coastal countries are aiming to balance climate change countermeasures and economic development by taking advantage of their geographical conditions and abundant natural resources. Kazakhstan, in particular, has extremely high wind and solar power generation potential, exceeding the world's wind power generation alone.possibilityIt is believed that there are also Such efforts are expected to not only help the country break away from its traditional dependence on fossil fuels, but also to strengthen its energy security. Furthermore, the establishment of a renewable energy import base is,EUThis is also an important step toward achieving a decarbonized society for the region. In the future, as these interregional partnerships develop, the Caspian region has the potential to become a central player in the international response to climate change.

For the Future of the Caspian Sea

The future of the Caspian Sea depends largely on the choices each country makes. Without cooperation and sustainable measures that go beyond immediate gains, the shrinking of this inland sea could have irreversible effects on the region's ecosystem, environment, and economy. In order to protect the Caspian Sea, which is renowned as the world's largest inland sea, now is the time for true cross-border cooperation.

Writer:Ito Risa

Graphic: Ayane Ishida

Follow @GNV_tweets